In this study, the effect of confounding factors on BP in hypertensives with high BP was investigated by comparing those in hypertensives with regulated BP. More than three quarter of the hypertensive patients who had admission to emergency department due to high BP had confounding factors. In the control group, about one-third of hypertensives with regulated BP had confounding factors. There was asignificant difference between thehypertensives of study and control groups in terms of their confounding factors.So, this study suggested that confounding factors impair BP control in patients with hypertension. A confounding factorshould be kept in mind in case of poor BP control in hypertensive patients. (7, 8, 11-15)
Mean systolic and diastolic BP were significantly higher in hypertensives having confounding factors than those without confounding factors in the study group. Furthermore, each confounding factor had significantly different effect on BP in hypertensives having confounding factors in the study group. In a study which investigated the influence of happiness, anger, and anxiety on the blood pressure of borderline hypertensives; happiness, anger, and anxiety increase BP to differing degrees. (13) Mean systolic BP of hypertensives who stated their confounding factor as ‘anger’ was significantly higher, and ‘sadness’ was significantly lower than those the remaining groups. Our finding was consistent with literature. The comparison of the pressures during each reported emotional state show that anger increase BP more than happiness. (13) In a study which investigated cardiovascular differentiation of happiness, sadness, anger, and fear, it was shown that anger, rather than fear, produced the greatest overall increases in BP. (15) In a research which investigated cardiovascular differentiation of emotions showed that sadness produced a distinct pattern with moderate increases in BP. (16)
We found that anxiety, anger, sadness, fatigue, poor sleep quality, unhealthy diet, depressed, and irregular medication seem to be confounding factors for elevated BP. In addition, mentioned as 'others' in this study, happiness, feeling tense, panic, sense of worthlessness, and sense of cheerless also were confounding factors for elevated BP.
In this study, anxiety was a confounding factor for elevated BP. Our finding was consistent with literature.Anxiety can activate the sympathetic nervous system, increase cardiac output, constrict blood vessels, and raise arterial BP. (18) First, anxiety increases BP in the short term, and the white coat effect derived from anxiety is a typical example. (19, 20) In a study which investigated association between anxiety and hypertension has shown that there was an association between anxiety and increased risk of hypertension. (21) It has been reported that patients with hypertension on antidepressant medications have lower BPs compared to those not on these medications possibly due to decreased baroreflex sensitivity and altered neuro-endocrine pathways. (22, 23)
In this study, about one-tenth of hypertensives in the study group were depressed. Depression is common in patients with uncontrolled hypertension and may interfere with BP control. In a study about hypertension, depression was a risk factor for poor BP control in hypertensive patients. (24) In another study about hypertension, it was shown that despite antihypertensive treatment, mean systolic and diastolic BP in patients with moderate/severe depression was significantly higher, than in group of patients without depression. (25)
In this study, we revealed ‘fatigue’ as confounding factor for elevated BP. On the contrary, in a research which investigated the relationship between fatigue and cardiac functioning, fatigue was not associated with BP at rest and no significant differences were found in heart rate or BP response between the various fatigue groups. (26)
In this study, poor sleep quality was a confounding factor for elevated BP and our finding was consistent with literature.Obstructive sleep apnea is common in patients with resistant hypertension, which is defined as BP that remains uncontrolled with three or more medications. (27) Insomnia with objective short sleep duration also is associated with increased hypertension risk. (27) Periodic limb movements in sleep increases BP, especially when associated with arousals. (27)
It was important to find that,especially after diet high in sodium, about one-tenth of hypertensives in the study group had admission to emergency department due to high BP. Adding salt into meals was significantly and independently associated with poor BP control. (8) Higher BP was associated with higher alcohol consumption, diet high in sugar-sweetened beverages and diet high in sodium. (9) Adherence to the Mediterranean diet pattern can be correlated with BP control. (28) Sodium reduction resulted in a significant decrease in BP of 3.5% in patients with hypertension. (29)